A three-dimensional atom probe sample comprising an alloy interface and a method of making the same

Abstract

The present application relates to the technical field of micro-nano scale material sample preparation, and particularly relates to a three-dimensional atom probe sample containing an alloy interface and a preparation method thereof. The method of the present application comprises the following steps: depositing a positioning block along the extension direction of the alloy interface on the surface of the region of interest on the surface of a substrate, then cutting a columnar sample on the substrate so that the positioning block is located on one of the side walls of the columnar sample, and then fixing the columnar sample on the sample loading surface of a sample stage. In the subsequent ion beam annular etching process, the positioning block material is different from the substrate material, so that the positioning block material can provide a good mass-thickness contrast in the ion beam annular etching process. Therefore, the defect of sample preparation failure caused by the weak contrast at the alloy interface and the difficulty in observing under an electron microscope can be effectively solved, and the success rate of sample preparation is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of micro- and nano-scale material sample preparation technology, and in particular to a three-dimensional atomic probe sample containing an alloy interface and its preparation method. Background Technology

[0002] Three-dimensional atomic probe microanalysis (3D Atomic Probe) employs local electrode atomic probe tomography, a high-performance measurement and analysis method with atomic-level spatial resolution. Based on the principle of "field evaporation," 3D Atomic Probe applies a strong voltage pulse or laser pulse to the sample, causing surface atoms to be converted into ions one by one, which are then removed and collected. The characteristic of 3D Atomic Probe is that it reveals the internal structure of materials point by point from the smallest scale, thus effectively addressing the challenging problems of measuring and analyzing small-scale structures in materials research, such as the size, composition, and distribution of precipitated phases or cluster structures; and the segregation behavior of elements at various internal alloy interfaces (grain boundaries, phase boundaries, interlayer alloy interfaces in multilayer films, etc.).

[0003] In current methods for preparing three-dimensional atom probe samples, focused ion beam (FIP) systems are commonly used for point-to-point sample preparation, requiring the sample to be a needle-like tip with a diameter of less than 100 nm. For special samples such as those at metal interfaces, the following main problems exist in the preparation of three-dimensional atom probe samples:

[0004] Grain boundaries are alloy interfaces between grains with the same structure but different orientations. At grain boundaries, atomic arrangement transitions from one orientation to another, thus the atomic arrangement at the interface is in a transitional state. Based on the magnitude of the orientation difference between adjacent grains, grain boundaries can be divided into small-angle grain boundaries and large-angle grain boundaries. When the orientation difference is less than 10°, it is called a small-angle grain boundary, which is composed of a series of edge dislocations spaced at a certain distance, and the grain boundary layer is relatively thin. When the orientation difference is greater than 10°, the orientation difference between most grains in metallic crystals is around 30° to 40°, therefore its grain boundaries are mostly large-angle grain boundaries. Under a scanning electron microscope, the different orientations of two adjacent grains at a grain boundary exhibit contrast differences under high beam current, thus allowing the determination of the grain boundary's outcrop location on the material surface.

[0005] For observing needle-tip samples at the interface of metallic materials, the traditional method of preparing needle-tip samples using focused ion beams generally involves etching perpendicular to the region of interest, i.e., grain boundaries extending into the material interior. A thin slice containing the grain boundaries is then vertically extracted and placed on the needle tip. Etching parameters and tip formation position are adjusted by observing the grain boundary position in real time. However, this method has an extremely low success rate. Because the grain boundaries are extremely fine and have weak contrast, they cannot be clearly observed under an electron microscope when circumferentially cutting the needle-tip sample. During the preparation process, the region of interest is easily lost, leading to sample preparation failure. This method often requires preparing multiple samples before one is successful.

[0006] Chinese invention patent CN 110082567 B discloses a method for preparing three-dimensional atomic probe samples by rotation. This method involves rotating an etched, triangular prism-like strip sample counterclockwise by 90° outside the instrument, then further exposing the resulting tip sample to a three-dimensional atomic probe laser. The resulting three-dimensional atomic probe data, after software reconstruction, yields data on the alloy interface and the microstructure on both sides of the interface, facilitating accurate analysis of the elemental distribution and structure within the tip sample. However, this method has a drawback: it requires continuous monitoring of the etching process throughout the subsequent etching phase. For example, in Example 2 provided in this patent, the layered alloy formed by Cr and ZrNiSn exhibits a highly visible dissimilar alloy interface, which is easily preserved within the tip sample. This method is suitable for samples with obvious layered structures and can prepare three-dimensional atomic probe samples at alloy interfaces between layers. Compared with the conventional preparation methods mentioned above, this method can ensure that the three-dimensional atomic probe samples can be collected more smoothly and are less prone to breakage. It can also ensure that the microstructures of interest in the material are preserved in the tip sample with a diameter of 100 nm. However, this method still has shortcomings for preparing tip samples at the interface of the same metal material: Unlike layered structures with obvious compositional differences, the grains on both sides of the grain boundary are of the same material and have the same structure. During the circumferential cutting process, the small orientation difference cannot provide enough contrast to make the grain boundary easy to observe. Even if the grain boundary is tilted 90°, it is still impossible to determine the location of the grain boundary. Therefore, the sample preparation is still very difficult. Summary of the Invention

[0007] To address the aforementioned technical problems, the present invention aims to provide a three-dimensional atomic probe sample containing an alloy interface and its preparation method. The three-dimensional atomic probe sample containing an alloy interface and its preparation method effectively solve the defects existing in the prior art and improve the success rate of preparing three-dimensional atomic probe samples containing an alloy interface.

[0008] To achieve the above-mentioned technical effects, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a three-dimensional atomic probe sample containing an alloy interface and a method for preparing the same, wherein the three-dimensional atomic probe sample containing the alloy interface comprises:

[0010] A conical needle-like specimen, wherein the conical needle-like specimen has an inclined bottom surface;

[0011] And a sample base located below the conical needle-shaped sample, the top surface of the sample base being fixedly connected to the inclined bottom surface of the conical needle-shaped sample, and the bottom surface of the sample base being horizontal, and the three-dimensional atomic probe sample of the alloy interface being able to be bonded to the sample carrying surface of the sample stage through the bottom surface of the sample base.

[0012] Preferably, the conical needle-shaped sample contains an alloy interface, which is a grain boundary of the same alloy or an alloy interface of different alloys.

[0013] Preferably, the tip diameter of the conical needle-like sample is 50-200 nm, and the tip is defined as the smaller end of the conical needle-like sample that is far from the sample base.

[0014] Secondly, the present invention also provides a three-dimensional atomic probe sample containing an alloy interface and a method for preparing the same, comprising the following steps:

[0015] A substrate is provided, and a region of interest is defined on the surface of the substrate, the region of interest including an alloy interface;

[0016] A positioning block is deposited on the surface of the region of interest, the positioning block at least covering part of the interface. Preferably, the positioning block material is different from the substrate and the long side of the positioning block is parallel to the extension direction of the alloy interface, so that the positioning block covers the alloy grain boundary as much as possible, thereby improving the success rate and yield of the final product preparation.

[0017] A columnar sample is cut from the substrate using a focused ion beam method, and the positioning block is attached to the first sidewall of the columnar sample.

[0018] The columnar sample is separated from the matrix and fixed to the sample stage. When the columnar sample is fixed to the sample stage, the first sidewall is almost perpendicular to the sample-carrying surface of the sample stage.

[0019] The columnar sample is etched by ion beam circumferential etching with the ion beam direction perpendicular to the sample stage until a conical needle-like sample containing an alloy interface is obtained.

[0020] Preferably, the alloy interface is a grain boundary of the same alloy or an alloy interface of different alloys; more preferably, the alloy interface extends from the interior of the matrix to the surface of the region of interest and can be observed under an electron microscope.

[0021] Preferably, the columnar sample is any one of a triangular prism, a square pyramid, or a pentagonal prism, and more preferably a triangular prism.

[0022] Preferably, the columnar sample is a triangular prism sample, which has a second sidewall and a third sidewall adjacent to the first sidewall. The second sidewall is almost perpendicular to the first sidewall. When the columnar sample is fixed to the sample stage, the second sidewall is almost parallel to the sample-carrying surface of the sample stage, and the first sidewall is almost perpendicular to the sample-carrying surface of the sample stage.

[0023] Preferably, the positioning block has a rectangular cross-section and a thickness not exceeding 1000 nm, and more preferably 100 nm to 500 nm.

[0024] Furthermore, the step of cutting the columnar sample includes:

[0025] The substrate is placed on the cutting table. Preferably, the substrate can be fixed to the cutting table by any of the following methods: clamping, bonding or welding.

[0026] The substrate is etched perpendicularly to the substrate surface along the long side of the positioning block on the first side to form a first groove;

[0027] The cutting stage is rotated while the direction of the focused ion beam remains unchanged. The substrate is obliquely etched along the long side of the positioning block towards the first groove on the second side of the positioning block to form a second groove. At least the end of the second groove is connected to the first groove, and the second side is opposite to the first side.

[0028] The substrate is etched at the first end of the positioning block to form a cantilever structure on the substrate;

[0029] The nanomanipulator is fixed to the cantilever structure, and then the substrate is etched by focused ion beam at the second end of the positioning block to completely separate the cantilever structure from the substrate, thereby obtaining a triangular prism-like sample, with the second end opposite to the first end.

[0030] Preferably, the step of fixing the columnar sample onto the sample stage includes:

[0031] The position of the nanomanipulator is adjusted so that the columnar sample is close to or in close contact with the sample loading surface of the sample stage. At this time, the first sidewall of the columnar sample is almost perpendicular to the sample loading surface of the sample stage.

[0032] A second adhesive material is deposited between the columnar sample and the sample-carrying surface of the sample stage until the columnar sample is fixed to the sample-carrying surface of the sample stage; preferably, the second adhesive material is Pt;

[0033] The columnar sample was separated from the nanomanipulator by focused ion beam etching.

[0034] Preferably, the ion beam ring etching includes:

[0035] First stage etching: The columnar sample is etched in the first stage with a first etching ring along the direction perpendicular to the sample carrying surface of the sample stage. The area of ​​the columnar sample located inside the first etching ring is the non-etched area. After the first stage etching, the non-etched area of ​​the columnar sample forms a cylindrical sample. The cylindrical sample contains both matrix and positioning block material in at least one cross section parallel to the sample carrying surface.

[0036] Second stage etching: The cylindrical sample is etched in the second stage with the second etching ring along the direction perpendicular to the sample stage until a conical needle-like sample is obtained. Preferably, the conical needle-like sample does not include positioning block material.

[0037] Preferably, the center of the first etched ring in the first stage is located on the plane at the interface between the substrate and the positioning block material, and the radius of the non-etched area does not exceed the thickness of the positioning block material.

[0038] Preferably, the second stage etching process includes the following steps:

[0039] Adjust the center position and / or size of the second etching ring as the etching time progresses.

[0040] Preferably, the ion beam ring etching further includes:

[0041] Grinding and Etching: The obtained cylindrical sample is ground and etched using a full-coverage ion beam along a direction perpendicular to the sample stage, thereby polishing and etching the tip of the conical needle-like sample.

[0042] / or polishing, and / or grinding, the outer wall of the conical needle-like sample is polished and / or ground.

[0043] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0044] First, the present invention provides a three-dimensional atomic probe sample containing an alloy interface, comprising a conical needle-like specimen and a sample stage located below the conical needle-like specimen, such that the conical needle-like specimen can be connected to the sample carrying surface of the sample stage through the sample stage. This three-dimensional atomic probe sample structure can greatly simplify the preparation process of the conical needle-like specimen.

[0045] Secondly, this invention provides a method for preparing a three-dimensional atomic probe sample containing an alloy interface. This method involves depositing a positioning block along the extension direction of the alloy interface on the surface of a substrate in a region of interest. Then, a columnar sample is cut from the substrate, with the positioning block positioned on one sidewall of the columnar sample. The columnar sample is then fixed to the sample-carrying surface of a sample stage. Finally, the columnar sample is etched in stages along a direction perpendicular to the sample-carrying surface of the sample stage using ion beam circumferential etching, ultimately obtaining a quasi-conical needle-like sample that meets the requirements. In this method, unlike conventional techniques that use deposited Pt material as a protective layer, this invention creatively uses the material deposited along the extension direction of the alloy interface as the positioning block. The positioning block material differs from the substrate material and provides better thickness contrast during ion beam circumferential etching, effectively solving the defect of weak contrast at the alloy interface, which makes observation under an electron microscope difficult and leads to sample preparation failure. Therefore, this method can significantly improve the success rate of alloy grain boundary sample preparation. Furthermore, the tip sample prepared by the method for preparing a three-dimensional atomic probe sample containing an alloy interface provided by the present invention has its grain boundary located in the central region of a conical tip sample, which allows for a large information collection area. Moreover, the alloy interface completely penetrates the conical tip sample, which is beneficial for accurately analyzing information such as grains, grain boundaries, segregation, and elements in the conical tip sample. Attached Figure Description

[0046] Figure 1 Electron micrograph of a positioning block deposited on a titanium alloy substrate, provided in an embodiment of the present invention;

[0047] Figure 2 Electron micrographs of cut triangular prism samples provided in embodiments of the present invention;

[0048] Figure 3 Electron micrographs of a triangular prism sample fixed by a nanomanipulator, provided in an embodiment of the present invention;

[0049] Figure 4 This is a schematic diagram of the process of ion beam ring cutting and etching of a prism-like sample provided in an embodiment of the present invention;

[0050] Figure 5 Provided for embodiments of the present invention Figure 4 A magnified schematic diagram of the local structure at point A;

[0051] Figure 6 Electron micrograph of the final conical needle-like sample obtained for an embodiment of the present invention;

[0052] The attached figures are labeled as follows: 10, titanium alloy substrate; 11, alloy interface; 20, positioning block; 30, triangular prism-like sample; 30a, cantilever structure; 301a, first groove; 301b, second groove; 302a, first sidewall; 302b, second sidewall; 302c, third sidewall; 40, nano-manipulator; 41, first adhesive material; 42, second adhesive material; 50, sample stage; 50a, sample carrier surface; 60, conical needle-like sample; 60a, inclined bottom surface; 61, sample base. Detailed Implementation

[0053] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0054] It should be noted that the terminology used in the embodiments of this application is for the purpose of describing specific embodiments only and is not intended to limit the embodiments of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0055] In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims. In the description of this application, it should be understood that the terms "first," "second," "third," etc., are used only to distinguish similar objects and are not necessarily used to describe a specific order or sequence, nor should they be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0056] Furthermore, in the description of this application, unless otherwise stated, "multiple" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0057] Unless otherwise specified, in this invention, terms such as "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," "x-direction," "y-direction," and "z-direction" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe orientation or positional relationships in this invention are for illustrative purposes only and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood in conjunction with the accompanying drawings and according to the specific circumstances.

[0058] Example 1

[0059] This embodiment provides a method for preparing a three-dimensional atomic probe sample containing an alloy interface. The equipment used in this embodiment is a FIB / SEM dual-beam system, where FIB stands for Focused Ion Beam and SEM stands for Scanning Electron Microscope.

[0060] This embodiment uses a Ti alloy to prepare a three-dimensional atom probe sample. Titanium alloys possess excellent properties such as high specific stiffness, high specific strength, high thermal strength, and corrosion resistance, and are widely used in the fabrication of lightweight, high-performance components for aerospace applications. The properties of titanium alloys depend on their microstructure, and grain boundaries are an important component of the titanium alloy microstructure. During the deformation process of titanium alloys, grain boundaries undergo deformation and damage. The deformation and damage of grain boundaries are closely related to the microstructure of the titanium alloy (such as the morphology, distribution, and properties of the primary α phase and the transformed β matrix). However, due to the extremely complex morphology and distribution of the primary α phase and the transformed β matrix, the inhomogeneity of these microstructures leads to extremely uneven stress distribution at the alloy interface during deformation, resulting in complex deformation and damage processes at the alloy interface. Therefore, the study of the grain boundary distribution of titanium alloys is of great significance for the application of titanium alloys. Three-dimensional atomic probe technology can examine the internal microstructure of titanium alloy materials point by point from the smallest scale. However, the technical difficulty lies in the fact that the grain boundaries of the same alloy are difficult to observe under a microscope, especially during the subsequent ion beam ring cutting and etching process, which can easily cause the loss of the region of interest. Therefore, it is often difficult to observe alloy grain boundaries in three-dimensional atomic probes prepared by traditional methods, resulting in a low sample preparation success rate.

[0061] In this embodiment, to address the aforementioned deficiencies, a method for preparing three-dimensional atomic probe samples containing alloy interfaces, which differs from traditional techniques, is employed. This method can accurately prepare three-dimensional atomic probe samples containing titanium alloy interfaces. Specifically, the method includes the following steps:

[0062] S1: Provide a titanium alloy substrate 10, and define a region of interest on the surface of the titanium alloy substrate 10. The region of interest includes an alloy interface 11, the position of which can be obtained by observation under a microscope.

[0063] S2: Please refer to Figure 1 A positioning block 20 is deposited on the surface of the region of interest to at least partially cover the region of interest. The positioning block 20 may be in a regular rectangular shape and is made of Pt, so that it is clearly distinguished from the titanium alloy substrate 10. The long side of the positioning block 20 is parallel to the extension direction of the alloy interface to improve the coverage of the alloy interface 11.

[0064] S3: Please refer to Figures 2-3 A triangular prism-like sample 30 was cut from the titanium alloy substrate 10 using a focused ion beam method, as follows:

[0065] The titanium alloy substrate 10 is horizontally fixed on a cutting table. Then, the titanium alloy substrate 10 is etched on the first side of the positioning block 20 along the long side of the positioning block 20 and perpendicular to the surface of the titanium alloy substrate 10 to form a first groove 301a. Then, the cutting table is rotated while keeping the direction of the focused ion beam unchanged. The titanium alloy substrate 10 is obliquely etched on the second side of the positioning block 20 along the long side of the positioning block 20 toward the first groove 301a to form a second groove 301b until the end of the second groove 301b communicates with the first groove 301a. The second side is opposite to the first side, thereby forming the first groove 301a and the second groove 301b on both sides of the positioning block 20, and the first groove 301a and the second groove 301b are connected.

[0066] Then, the titanium alloy substrate 10 is etched at the first end of the positioning block 20 to form a cantilever structure 30a on the titanium alloy substrate 10. Finally, the nanomanipulator 40 is brought close to the first end of the positioning block 20 and fixed to one end of the cantilever structure 30a by depositing a first adhesive material 41, which can be Pt. At this time, the titanium alloy substrate 10 is etched at the second end of the positioning block 20 to completely separate the cantilever structure 30a from the titanium alloy substrate 10 to obtain a triangular prism-like sample 30. It should be noted that the second end is opposite to the first end.

[0067] Through the above cutting, a triangular prism-like sample 30 can be separated from the titanium alloy substrate 10. When the triangular prism-like sample 30 is cut, the positioning block 20 is attached to the first sidewall 302a of the triangular prism-like sample 30. At the same time, the triangular prism-like sample 30 also has a second sidewall 302b and a third sidewall 302c. The second sidewall 302b is formed when etching the first groove 301a and is almost perpendicular to the first sidewall 302a. The third sidewall 302c is formed when etching the second groove 301b and connects the first sidewall 302a and the second sidewall 302b.

[0068] S3: Please refer to Figure 4 The quasi-triangular prism sample 30 is separated from the titanium alloy substrate 10, and the quasi-triangular prism sample 30 is fixed onto the sample stage 50. When the quasi-triangular prism sample 30 is fixed onto the sample stage 50, the first sidewall 302a is almost perpendicular to the sample-carrying surface 50a of the sample stage 50. The fixing method is as follows:

[0069] The position of the nanomanipulator 40 is adjusted so that the quasi-triangular prism sample 30 is close to or in close contact with the sample-carrying surface 50a of the sample stage 50. At this time, the first sidewall 302a of the quasi-triangular prism sample 30 is almost perpendicular to the sample-carrying surface 50a of the sample stage 50. Then, a second adhesive material 42 is deposited between the quasi-triangular prism sample 30 and the sample-carrying surface 50a of the sample stage 50 until the quasi-triangular prism sample 30 is fixed to the sample-carrying surface 50a of the sample stage 50. The second adhesive material 42 may be the same as or different from the first adhesive material 41. Preferably, the second adhesive material 42 is the same as the first adhesive material 41 and both are Pt.

[0070] S4: Please refer to Figure 4 (a) Once the triangular prism-like sample 30 is stably bonded to the sample stage 50, the triangular prism-like sample 30 is then separated from the nanomanipulator 40 by focused ion beam etching. The sample stage 50 can be a focused ion beam carrier.

[0071] S5: Please refer to Figure 4(b), 4(c), and 4(d) describe the process of ion beam circumferential etching of the triangular prism-like sample 30 until a conical needle-like sample 60 containing the alloy interface 11 is obtained. The aforementioned ion beam circumferential etching specifically includes a first-stage etching, a second-stage etching, and a polishing etching. Specifically, the purpose of the first-stage etching is to obtain a cylindrical sample from the triangular prism-like sample 30. The purpose of the second-stage etching is to obtain a conical needle-like sample 60 based on the cylindrical sample etched in the first stage. The purpose of the polishing etching is to polish and grind the tip and outer wall of the conical needle-like sample 60 to make its surface smooth. More specifically, the methods for the aforementioned first-stage etching, second-stage etching, and polishing etching are as follows:

[0072] S51: First stage etching:

[0073] Please see Figure 4 (b) The first etching ring formed by ion beam ring cutting is used to perform the first stage etching on the triangular prism sample 30 in a direction perpendicular to the sample carrying surface 50a of the sample stage 50. The center of the first etching ring can be located on the plane where the interface between the titanium alloy substrate 10 and the positioning block 20 material is located or on the side of the interface between the titanium alloy substrate 10 and the positioning block 20 material close to the titanium alloy substrate 10. At this time, the positioning block 20 formed by the Pt material is located on the side of the alloy interface 11 to be obtained. Since the material of the positioning block 20 is significantly different from that of the titanium alloy substrate 10, the positioning block 20 can be used as a reference point for determining the location of the alloy interface 11 during the etching process.

[0074] During the first stage of etching, the radius of the non-etched area does not exceed the thickness of the positioning block 20 material and remains unchanged throughout the first stage of etching. During this process, the area of ​​the triangular prism sample 30 located inside the first etching ring is the non-etched area. After the first stage of etching, the non-etched area of ​​the triangular prism sample 30 forms a cylindrical sample. Therefore, in this cylindrical sample, it contains both the titanium alloy substrate 10 and the positioning block 20 material in at least one cross-section parallel to the sample loading surface 50a of the sample stage 50. Thus, the success rate of sample preparation can be guaranteed.

[0075] S52: Second stage etching:

[0076] Please see Figure 4(c) The second etching ring formed by ion beam ring cutting etching is used to perform a second stage etching on the cylindrical sample in a direction perpendicular to the sample carrying surface 50a of the sample stage 50 until a conical needle-shaped sample 60 is obtained. During this process, the center position and size of the second etching ring can be adjusted as needed according to the etching time, so as to etch the aforementioned cylindrical sample into a conical needle-shaped sample 60. In this process, the material of the positioning block 20 can be completely removed. To achieve the aforementioned effect, how to adjust the center position and the size of the second etching ring is a conventional technique mastered by those skilled in the art, so it will not be described in detail here.

[0077] It should be noted that, during the second stage of etching, in order to further ensure the success of sample preparation, the diameter of the successfully prepared conical needle-shaped sample 60 can be approximately equal to the radius of the cylindrical sample, so that the material of the positioning block 20 is completely removed and the alloy interface 11 to be analyzed is contained in the prepared conical needle-shaped sample 60 with the highest probability.

[0078] S53: Polishing and etching:

[0079] Please see Figure 4 (d) The obtained cylindrical sample is polished and etched by a full-coverage ion beam along the sample carrier surface 50a perpendicular to the sample stage 50, thereby polishing and grinding the tip and outer wall of the conical needle-shaped sample 60 to make its surface smooth and to make it reach the final size.

[0080] Example 2

[0081] Please see Figures 5-6 Based on the method for preparing a three-dimensional atomic probe sample containing an alloy interface provided in Embodiment 1 above, this embodiment provides a three-dimensional atomic probe sample prepared using the above-described method for preparing a three-dimensional atomic probe sample containing an alloy interface. This three-dimensional atomic probe sample has the following structure, which clearly distinguishes it from three-dimensional atomic probe samples prepared by conventional methods. Specifically, it includes:

[0082] A conical needle-like specimen 60, wherein the conical needle-like specimen 60 has an inclined bottom surface 60a;

[0083] And a sample stage 61 located below the conical needle-like sample 60. The sample stage 61 is made of Pt material and its function in the preparation process is to fix the triangular prism-like sample onto the sample carrying surface 50a of the sample stage 50. The top surface of the sample stage 61 is fixedly connected to the inclined bottom surface 60a of the conical needle-like sample 60, and the bottom surface of the sample stage 61 away from the conical needle-like sample 60 is horizontal. The three-dimensional atomic probe sample containing the alloy interface 11 can be bonded to the sample carrying surface 50a of the sample stage 50 through the bottom surface of the sample stage 61. The sample stage 50 can be a focused ion beam carrier. After the conical needle-like sample 60 is prepared, its tip diameter is controlled between 50 and 200 nm. The aforementioned "tip" is defined as the smaller end of the conical needle-like sample 60 that is away from the sample stage 61.

[0084] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications and substitutions should be covered within the scope of the claims of the present invention. Technical aspects, shapes, and structures not described in detail in this invention are all well-known technologies.

Claims

1. A method for preparing a three-dimensional atomic probe sample containing an alloy interface, characterized in that, Including the following steps: A substrate is provided, and a region of interest is defined on the surface of the substrate, wherein the region of interest contains an alloy interface; the alloy interface is a grain boundary of the same alloy or an alloy interface of different alloys. A positioning block is deposited on the surface of the region of interest, the positioning block at least partially covering the alloy interface, the positioning block material is different from the substrate material, and the long side of the positioning block is parallel to the extension direction of the alloy interface; the cross-section of the positioning block is rectangular. A triangular prism-like sample is cut from the substrate, and the positioning block is attached to the first sidewall of the triangular prism-like sample; The prism-like sample is separated from the substrate, and a second adhesive material is deposited between the prism-like sample and the sample-carrying surface of the sample stage until the prism-like sample is fixed to the sample-carrying surface of the sample stage. When the prism-like sample is fixed to the sample stage, the first sidewall is almost perpendicular to the sample-carrying surface of the sample stage. The ion beam is circumferentially etched onto the sample-carrying surface of the sample stage with the ion beam motion direction perpendicular to the sample stage until a conical needle-like sample containing an alloy interface is obtained. The conical needle-like sample has an inclined bottom surface and a sample base located below the conical needle-like sample. The top surface of the sample base is fixedly connected to the inclined bottom surface of the conical needle-like sample, and the bottom surface of the sample base is horizontal. The conical needle-like sample contains an alloy interface. The ion beam ring etching includes: First stage etching: The triangular prism sample is etched in the first stage with a first etching ring along the direction perpendicular to the sample carrying surface of the sample stage. The area of ​​the triangular prism sample located inside the first etching ring is the non-etched area. After the first stage etching, the non-etched area of ​​the triangular prism sample forms a cylindrical sample. The cylindrical sample contains both matrix material and positioning block material in at least one cross section parallel to the sample carrying surface. Second stage etching: The cylindrical sample is etched in the second stage with the second etching ring along the direction perpendicular to the sample stage until a conical needle-like sample is obtained, wherein the conical needle-like sample does not include the positioning block material.

2. The method for preparing a three-dimensional atom probe sample containing an alloy interface as described in claim 1, characterized in that, The prism-like sample has a second sidewall and a third sidewall adjacent to the first sidewall. The second sidewall is almost perpendicular to the first sidewall. When the prism-like sample is fixed to the sample stage, the second sidewall is almost parallel to the sample-carrying surface of the sample stage.

3. The method for preparing a three-dimensional atom probe sample containing an alloy interface as described in claim 1, characterized in that, The steps for cutting the triangular prism sample include: Place the substrate on the cutting table; The substrate is etched perpendicularly to the substrate surface along the long side of the positioning block on the first side to form a first groove; The cutting table is rotated, and the substrate is obliquely etched along the long side of the positioning block toward the first groove on the second side of the positioning block to form a second groove, and at least the end of the second groove is connected to the first groove, and the second side is opposite to the first side. The substrate is etched at the first end of the positioning block to form a cantilever structure on the substrate; The nanomanipulator is fixed to the cantilever structure, and then the substrate is etched at the second end of the positioning block to completely separate the cantilever structure from the substrate, thereby obtaining a triangular prism-like sample, with the second end opposite to the first end.

4. The method for preparing a three-dimensional atom probe sample containing an alloy interface as described in claim 3, characterized in that, The steps of fixing the triangular prism-like sample onto the sample stage include: The quasi-triangular prism sample is fixed to the sample carrier surface of the sample stage, and the position of the nanomanipulator is adjusted so that the quasi-triangular prism sample is close to or in close contact with the sample carrier surface of the sample stage. At this time, the first sidewall of the quasi-triangular prism sample is almost perpendicular to the sample carrier surface of the sample stage. The second adhesive material is Pt; After the triangular prism-like sample is fixed to the sample carrier surface of the sample stage, the triangular prism-like sample is separated from the nanomanipulator by focused ion beam etching.

5. The method for preparing a three-dimensional atom probe sample containing an alloy interface as described in claim 1, characterized in that, The center of the first etched ring in the first stage is located on the plane at the interface between the substrate and the positioning block material, and the radius of the non-etched area does not exceed the thickness of the positioning block material.

6. The method for preparing a three-dimensional atom probe sample containing an alloy interface as described in claim 1, characterized in that, The second stage etching process includes the following steps: Adjust the center position and / or size of the second etching ring as the etching time progresses.

7. The method for preparing a three-dimensional atom probe sample containing an alloy interface as described in claim 1, characterized in that, The ion beam ring etching also includes: Grinding and etching: The obtained cylindrical sample is ground and etched with a full-coverage ion beam along a direction perpendicular to the sample carrying surface of the sample stage, thereby polishing and / or grinding the tip of the conical needle-shaped sample, and / or polishing and / or grinding the outer wall of the conical needle-shaped sample.

8. The method for preparing a three-dimensional atom probe sample containing an alloy interface as described in claim 1, characterized in that, The tip diameter of the conical needle-like sample is 50–200 nm.

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